Give some stream of consciousness and then the answer. Obama defeated Romney, winning a majority of both the popular vote and the Electoral College. Obama won 51.1 % of the popular vote compared to Romney's 47.2 %, while Libertarian nominee Gary Johnson won just under 1 % of the vote. Obama was the first incumbent since Franklin D. Roosevelt in 1944 to win reelection with fewer electoral votes and a lower popular vote percentage than had been won in the previous election, and was also the first two-term president since Ronald Reagan to win both his presidential bids with a majority of the nationwide popular vote.

Answer this question: who won the popular vote in the 2012 presidential election?
The important part for answering this question is: Obama defeated Romney, winning a majority of both the popular vote and the Electoral College.
Therefore, the answer is Obama.